Trial Review

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The Sugars Intake Measurement Study: A study to investigate the association between carbon and nitrogen stable isotope ratios as a biomarker of sugars intake in 120 healthy participants in New Zealand

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Scientific title

Validation of carbon stable isotope ratios in red blood cells and hair as a biomarker of sugars intake in New Zealand

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Secondary ID [1]2902180

Nil known

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Universal Trial Number (UTN)

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Trial acronym

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Linked study record

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Health condition

Health condition(s) or problem(s) studied:

Biomarker development of sugars intake.3003960

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Condition category

Condition code

Diet and Nutrition30025930025900

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Other diet and nutrition disorders

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Intervention/exposure

Study type

Observational

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Patient registry

False

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Target follow-up duration

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Target follow-up type

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Description of intervention(s) / exposure

We will determine carbon and nitrogen stable isotope ratios in blood and hair samples as biomarkers of free sugars intakes. Blood and hair samples will be taken at baseline, and again 10 weeks later. During the 10 weeks, participants will complete a 7d diet record and two different food frequency questionnaire (FFQ) (a general FFQ and a sugar-specific FFQ).

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Intervention code [1]2959870

Not applicable

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Comparator / control treatment

Free sugars will be estimated by conventional dietary assessment methods including a general short food frequency questionnaire (FFQ), a sugars-specific FFQ and a 7d weighed diet record.

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Control group

Active

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Outcomes

Primary outcome [1]2997400

The association between carbon and nitrogen stable isotope ratios in red blood cells and self-reported dietary intakes of total sugars, free sugars, and added sugars.

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Timepoint [1]2997400

10-week follow up

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Primary outcome [2]2997410

The association between carbon and nitrogen stable isotope ratios in hair and self-reported dietary intakes of total sugars, free sugars, and added sugars.

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Timepoint [2]2997410

10-wk follow up

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Secondary outcome [1]3279740

The association between self-reported dietary intakes of total sugars, free sugars, and added sugars measured using a short FFQ, a sugars-specific FFQ, and a 7d diet record.

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Timepoint [1]3279740

10-wk follow up

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Eligibility

Key inclusion criteria

Healthy adults, aged 18-65 years, and a BMI < 27 kg/m2

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Minimum age

18Years

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Maximum age

65Years

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Gender

Both males and females

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Can healthy volunteers participate?

Yes

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Key exclusion criteria

None

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Study design

Purpose

Screening

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Duration

Longitudinal

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Selection

Random sample

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Timing

Both

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Statistical methods / analysis

Power calculations indicate that 100 participants should be sufficient to detect a correlation of 0.3 between free sugars intakes, estimated from weighed diet records, and d13C. We will allow for a drop out rate of 20% giving a sample size of 120 subjects.

Seven recording days are required to capture habitual dietary intake of participants. Diet records will be analysed for major nutrients including free and total sugars using Kai-calculator software and the New Zealand Food Composition Database, and the average daily intake for energy, macronutrients, free and added sugars, and dietary fibre will be calculated.

Relative validity of the d13Cversus mean intakes of free sugars estimated weighed diet records (7 days total per person) will be assessed using Spearman correlation coefficients (SCC). Bland-Altman analyses will be performed to assess the strength of agreement between the d13C and 7d weighed diet record in measuring sugars intakes. Repeated measures two-way ANOVA will be used to assess the between-subject effect and to compare bulk d13C in various tissues at each monthly time point with adjustment for potential confounders including age, sex, body size, hair thickness, physical activity level and total energy intake.

Correlation coefficients (r) measured between nutritional biomarkers and reported dietary intake vary widely in research trials, with typical r values ranging from 0.03-0.70, with a mean of 0.39. These correlations may be interpreted as weak to modest, as they may underestimate the true validity of biomarkers due to the inherent inaccuracy of self-reported dietary intake measures. R values of 0.5-0.7 are typically considered acceptable as a precision in dietary validation studies.

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Recruitment

Recruitment status

Not yet recruiting

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Date of first participant enrolment

Anticipated

20/11/2016

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Actual

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Date of last participant enrolment

Anticipated

1/03/2017

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Actual

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Date of last data collection

Anticipated

24/04/2017

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Actual

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Sample size

Target

120

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Accrual to date

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Final

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Recruitment outside Australia

Country [1]82630

New Zealand

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State/province [1]82630

Otago

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Funding & Sponsors

Funding source category [1]2945820

Government body

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Name [1]2945820

Health Research Council of New Zealand

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Address [1]2945820

Auckland Office:

Level 3, 110 Stanley St, Grafton, Auckland 1010

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Country [1]2945820

New Zealand

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Primary sponsor type

Government body

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Name

Health Research Council of New Zealand

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Address

Office in Auckland:Level 3, 110 Stanley St, Grafton, Auckland 1010

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Country

New Zealand

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Secondary sponsor category [1]2934590

None

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Name [1]2934590

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Address [1]2934590

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Country [1]2934590

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Ethics approval

Ethics application status

Approved

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Ethics committee name [1]2960230

University of Otago Human Ethics Committee (Health)

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Ethics committee address [1]2960230

The Academic Committees OfficePO Box 56Dunedin 9016New Zealand

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Ethics committee country [1]2960230

New Zealand

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Date submitted for ethics approval [1]2960230

10/10/2016

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Approval date [1]2960230

09/11/2016

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Ethics approval number [1]2960230

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Summary

Brief summary

Restriction of free sugars is an almost universal recommendation despite a relatively high degree of inconsistency in the evidence base linking free sugars with health risks. Food industry continues to debate the relevance of sugar reduction strategies thus ongoing research to investigate the effects of sugar on population health is needed. Nutritional studies typically assess free sugars intakes using self-report methods which are subject to substantial misreporting thus observed diet-disease relationships are frequently obscured. Previous research in the U.S. has shown that carbon stable isotope ratios could be used as a objective measure of intakes of free sugars. The carbon stable isotope composition of a sweetener reflects the isotopic composition of the plant from which it originated. In NZ the majority of sweeteners are derived from sugar cane which has a distinctive d13C signature compared with other plant-derived foods and preliminary research has shown that d13C values in various tissues correlates with consumption of sugar-sweetened foods and drinks. For the validation current study, we will recruit 120 volunteers, measure the carbon stable isotopes in blood and hair samples as biomarkers of free sugars intakes and validate these markers against intakes of free sugars estimated by conventional dietary assessment methods including a general short food frequency questionnaire (FFQ), a sugars-specific FFQ and a 7d weighed diet record.